cancel_instance

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare the safety profile: readOnly false, openWorld true, idempotent false, and destructive false. The description adds only that cancellation can happen at any time for a previously created instance, without explaining the resulting state, reversibility, or how cancellation differs behaviorally from stopping or shutting down.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The action is front-loaded and the description is short. There is a typo in 'Your are' and the second sentence adds limited value, but it remains concise and structurally easy to parse.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The parameter schema is fully documented and annotations provide a safety profile, but the description does not resolve the important ambiguity between canceling, stopping, and shutting down an instance. For a lifecycle mutation with a nested request body and no output schema, that gap leaves the definition only minimally complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so parameter meanings are already documented, including instanceId and the nested body with cancelDate. The description adds no syntax or semantic detail beyond the schema's coverage, so the baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: cancel a specific instance by id, and includes the endpoint. It is clear what the tool does, but it does not differentiate cancellation from nearby instance lifecycle actions such as instance_stop or instance_shutdown.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The phrase 'previously created instance' and 'at any time' gives some implied usage context. However, it does not explicitly say when to use this instead of instance_stop, instance_shutdown, or other lifecycle alternatives, nor does it state exclusions or preconditions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.